Acoustic inspection of distribution networks is seen as one of the main tools for finding problems in electrical equipment at an early stage. As is often the case with predictive methods, the analysis of the detected phenomena may reveal valuable information about the integrity of the equipment. Therefore, this article aims to evaluate the phenomena detected in a distribution network, focusing mainly on the occurrence of partial discharges through ultrasonic inspection. A digital ultrasonic testing device was used to detect acoustic signals emitted from an overhead distribution system, thus allowing to acquire more experience in electrical equipment inspection, as well as in identification of partial discharges.